Power transmission



June 5, 1945. J. F. JEANNIN,

POWER TRANSMISSION Filed July 10, 1942 3 Sheets-Sheet 2 INVENTOR. JOHNF. JEANNIN O w M. m 4 m o B \\l.! II! n n I l 4 l a l H ATTORNEY.

June 5, 1945.

J. F. JEANNIN POWER TRANSMISSION Filed Jul y 10, 1942 '3 Sheets-Sheet 3INVEN TOR.

.JOHN F. JEANNIN WX.W

ATTORNEY.

' ure 1. I p i Figure 'i'is across section on line 7-1 of Figure 1. l

UNITED, STATES... PATENT OFFICE POWER- TRANSMISSION John F. Jeannln,Detroit, Mich., assignor to Vickers Incorporated, Detroit, Mich.,

ration of Michigan Application July 10, 1942, Serial No. 450,368

' 3 Claims. (01. 103-11) This invention relates to power transmissions,particularly to those of the type comprising two or more fluid pressureenergy translating devices, one of which may function as a pump andanother as a fluid motor.

The invention is more particularly concerned with a compound pump unit.There is disclosed in thepatent to Harry F. Vickers, No. 2,218,565, r

a compound, positive-displacement pump circuit wherein two or more pumpsmay be operated in parallel with the delivery pressure which they arepumping against low or moderate and, when such allel or in seriesdepending upon delivery pressure.

It is a further object to provide a structure of this character havingcertain constructional advantages contributing to reliability and longlife as well as to ease of maintenance;

ings, there is illustrated a, unitary structure generally designated it!having two, cylindrical recesses l2 and it in axial alignment and withinwhich are mounted rotary pumping cartridges or units It and It. Thelatter may be of any suit-- able type and as shown are similar to thevane pump described in the patent to Harry F, Vickers,

No, 1,989,900. It will be understood that, although many of the detailsof the construction of such patented pump are omitted from the followingdescription, they may of course be considered as present in such unitsby reference.

Rotary units l6 and i8, as shown in Figures 4 and .7, are identical'inconstruction and comprise respectively. The inner surfaces of ringmembers and 22 are substantially elliptical in shape to generally formthe balanced working chambers 28 and 30, respectively. 'I'hegreater partof the surfaces of the rings 20 and 22, which define the Further objectsand advantages of the present invention will be apparent from thefollowing description, reference being had to the accompanying drawingswherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure 1 is atop view of a pumping unit showing particularly therelative arrangement of passageways and valves.

Figure 2 is a cross section on line 2-2 of Figure 1 showing a preferredform of the present invention.

ure 1.

Figure 4. is a cross section on ure 1. I

sure 5 is a cross sectionon ure'i.

Flgure Gis-across line 4-4 of Figsection on line 8-8 of Fig- FigureBisReferring now toli'igures 1 as 2 oftlie drawniieu s orri across sectionon line 8-! of Fig means for the head A The bushing units consist and42, which support the Figure 3 is a cross section-on line I4 of Fig- Iure 2). The latter. are

working chambers 28 and 30, are substantially concentric as are also thediametrically positioned portions 32 and 34 thereof which receive andsupport the main body of the rotors. By design pump I I8, a first-stageunit, has a slightly larger volumetric output or capacity than pump it,a secondstage unit.. This isaccomplished by forming the ellipticalcontour of the ring member 20 of pump IS with a slightly larger ,minordiameter than that of ring member 22, their respective maior diame--ters being equal.

The rotors of units I5 ure 2, are alsosupported one-piece bushingunitsand It, as shown in by oppositely-positioned, 36 and 38,respectively.

and laterally extending flanges 44 and 46, respectively. Each bushingunit is provided with a seallug-ring at and 49. Flanges 44 and 48 of thebushing units are provided with concentric, cir- V cumferentiallyspaced, a'rcuate and relatively long and outlet ports 52 and 54,respectively (see Figures! and '1) -Pumpunits i8 and are retained intheir reand narrowinlet ports 48 and motive recessesby head plates 58and 58 (Figindependently mounted- I and adap ed to snugly fit within therecesses l2 and It to insure equal pressure over their respective units,Head plates 56 and 58 are adjustably secured by means of bolts and I2,respective to the main body structure Ill. Also mounted thereto, bymeans of bolts 83 and 85, are bearing plates 64 and which carry ballbearings 08 and 10, respectively, in

annular liner rings 20 and 22 which are secured. to the main bodystructure 10 by screws 24 and 28,

of bearing members 40, bearings of the rotors,

distribution of clamping which the ends of a shaft 12 are rotatablymounted. 'It will be noted that the bearing plates 64 and 66 are mountedindependently of the head plates 68 and 68 and of the shaft 12, and canbe securely aflixed without disturbance of the setting of the headplates. Likewise, the adjustment of head plates 66 and68 can in no wayaffect the alignment of the shaft bearings. Shaft 12 is f splined at 14and 16 to slidably receive a broached complementary splined portionformed in the rotors of units I6 and I8 to provide a driving connectiontherefor.

Head plates 66 and 58 are provided with sealin rings 18 and 80 on theirperiphery which communicate with the pressure side of their respectivepumps through passages 82 and 84, as best shown to be described.

in Figure 9. The head plates 66 and 68 also ini clude drilled passages86 and 88 through which leakage fluid is drained to internal chambers 81and 89 thereof. The latter-chamber communicates with the suction side ofthe pump I8 through an obliquely extending passage 80. This provides forinternal drainage of the unit I0 by having the fluid drained intochamber 81 of the head plate 56pass through the splines of the shaft 12and into chamber 89 of the head plate 68, where it is withdrawn-by pumpI8 through a passage 80 (see Figure 8). End caps 92 and 84 are mountedon the bearing plates 64 and 66 by screws 86 and 88, respectively(Figure 2). End cap 64, because of internal drainage, carries a sealingring I00 arranged to prevent the escape of oil from within and theadmission of air from without. The main'body structure I0, as shown inFi ures 4 and '7, is provided with cored inlet passages I02 and I04which have'arcuate branch portions extending partially around the shaft12, disposed radially outward thereof to connect with the suction ports48 and 50 of the pump units I6 and I8, respectively. The branch portionsof the inlet cores I02 and I04, as shown in Figure8, envelope theirrespective rotors, providing for the intake of liquid from both sidesthereof to eliminate cavitation in filling the work chambers of the pumprotors.

Pressure core II8 (Figure 5) connects with a passage I34 which extendsto the upper side of the unit I0 forming a delivery conduit therefor,and is intersected by a transverse bore I36, while pressure core I20(Figure 6) connects with a passage I38 which leads to a transverse boreI40.

It will be noted from Figure 4 that the unit I0 is provided. with twosuction check valves I06 and two pressure check valves I30 for thepurpose of rendering it compact and symmetrical about its axis. The useof two check valves also enables their action to' be more rapid andreliable.

Mounted in transverse bores I36 and I40 (Figures 5 and 6) are relief.and sequence valves I42 and I44, respectively. As shown in Figures3-and' 5, relief valve I42 comprises a piston I46 slldably mounted inbore I36 and having an extended valve portion I48 normally closing theseat I50 under pressure of a light spring I52. Piston I48 is providedwith an orifice I54 therethrough and a tubular pilot I56 slidable inbore I58 in an end cap I60. The latter is secured to the outer face ofthe body I0 to close the bore I 36 and to provide a control chamber I62for the relief valve piston I46. A passage I 64 extends between theBriefly, the valve I46 acts to maintain a Dredetermined pressure inpassage I34 (Figure 5) by opening and discharging excess fluid intopassage These valves may be constructed cores I02 and I04 and carry anannular seat- IIO against which the check valve is normally urged intocontact by a spring II2, the latter 3 abutting against a plug II4. CoreI04 (Figure 7) is provided with a branch portion II6 which extendstherefrom to the bottom portion or theunit I0- to form a suction inletfor the two pump units I8 and I8. The former unit draws fluid throughthe bores III (Figure 8) which are open to free flow from passage I04but areclosed automatically by check valves I06 to flow in the oppositedirection, as during series operation hereinafter disclosed. I l

The body I0 is also provided with cored pressure passages H8 and I20(Figures 5 and 6) which have 'arcuate branch portions extending aroundthe shaft 12, disposed radially thereof to connect with the pressureports .62 and 54' of the pump units I6 and I8, respectively (Figure 9).As shown in Figure 8, the pressure cores I I8 and I20 extend upwardlybeyond the pump units and are I12. Whenever a predetermined pressure isreached, it causes the spring-loaded ball relief valve I66 to open andrelievecontrol chamber I62 of liquid at a rate faster than can besupplied through the orifice I54. This causes the piston I46 to becomeunbalanced and move to the right away from its seat I50 untilsufiicientpressure is restored to th control chamber I62. Since pilot relief valveI66 is backed up so to speak by the pressure, if any, in inlet core I02,the predetermined pressure above referred to is measuredover and abovethat existing in core I02.

Sequence valve I44 (Figures 3 and 6) comprises I a valve spool I14slidably mounted in the bore I40 and normally biased upward (Figure 3)by a spring I16 to cut oil port I18 from port I80. Port I18 connectswith the passage I38 (Figure 6) .while port I connects with apassage I82'(see Figure '7) which extends to a core I84. The lat-. ter extendslongitudinally across the side of the body I0 and communicates with theinlet cc of pump I6 (see Figure 4).

The upper end of the bore I 40. (Figure 3) of sequence valve I44 isclosed by an end cap m;em

ber I86 containing a bore I68 in which is mounted .j an adjusting screwI for varying the pressure setting or a spring I82. The latter ispositioned intermediate two spring guides I84 and I88, the

separated-by a common wall I22 through which 7 /former abuttingagainst apiston I88 mounted in bore 200. The latter is responsive to pressure inthe delivery conduit I 84 through passages 202 and is arranged toconnect the pressure therein with the top of valve spool I I4 wheneverthe setting of the spring I 92 has been reached.

End cap member I88 includes passages 204 (see Figure '7) which connectthe bore I88 and the bottom of valve spool I14 with the inlet core I04to provide a drain therefor.

The unit I also incorporates a pressure dividing valve 208 (Figure 2)which causes the pumps l6 and I8each to carry its proportionate share ofthe main pressure during series flow, hereinafter described. Valve 208comprises a diilerential piston 208 mounted in a sleeve 2 ldwhichisfixed in a bore 2I2. Piston 208 has an area diife'rential of one totwo, of which the largerarea end communicates with the inlet core I02 ofpump I8 through passage I10, and the smallerarea end communicatesthrough passage 2 I4 with the pressure core H8 of pump I8. It will beremembered that core 8' connects with the passage I34 (Figure 5) whichforms the delivery conduit for the pumping unit I0, thus constantlyexposing the small end of pressure dividing valve 208 to the workpressure of the circuit. Valve 208 is provided with a return conduit2l5, shown by dotted lines in Figure 2 for sake of clarity althoughproperly lying above the plane of the paper, which connects port 2I8 ofsleeve 2I'0 (Figure 2) to the inlet core I04 (Figure 7) of pump unit I8.

(Figure 8) into the core -I I8.

With the parts of the control valves in the positions shown; thecombined flow of the pump units I6 and I8 passes through the deliveryconduit I34 to the work circuit so longas the pressure therein remainsbelow the setting of the sequence valve I44. Suchflow is indicatedthroughout the figures by solid arrows.

' It will be understood that the relief valve I42 is normally set forthe maximum pressure of either pump unit, e. g., 1,000 p. s. 1., whilethe sequencevalve I44 is given a pressure setting slightly below that ofrelief valve I42, e. g., 950

ports I'IB and I80 thereof. This will bypass the delivery of pump I8through passages I18, I80, I82 and I84 (Figures 6 and 7) to the inletcore I02 of the pump unit I8 (Figure 4). This how and that hereafterdescribed are shown by dotted lines.

Pump I8 was previouslypulling oil through the check valves I08, and thepressure dividing valve 208 was held closed by pressure in core II8.However, after the opening of the sequence valve I44, pump It willreceive its supply from the passages I82 and I84, and, as this fluid isunder pressure, it will cause check valves I08 to close.

'Pump I8 having a slightly larger capacity than pump I8, the surplusoil-is returnedthrough the pressure dividing valve 208 to the inlet coreI04 of the pump unit I8. As hereinbefore disclosed, the pressuredividing valve 208 is so constructed that the working pressure areaexposed to the pressure core- II8 has a definite relationship to theworking pressure area exposed to the inlet core I02 of the pump I8. Thisrelationship being oneto two in the present example, the'pressure incore I02 of the pump I8.will be one-half the pressure in the deliverycore II8. This relationship is maintained by valve 208 lying in aslightly open position such that the excess volume delivered by pump I8above that taken in by pump I8 is bypassed from passage 2I4 to passage2I5' (Figure 2).

The action of the present pump circuit and its control valve is morefully described in the patent to Harry F. Vickers, 2,218,565, towhichrefer- 'ence is made for more detailed consideration of operation.

It will be seen that the present device provides an extremely compactunitary structure containing all the mechanism necessary to provide fordelivery of oil at a given volume and pressure by operating the twopumps in parallel or for delivery at half that volume and double thatpressure by operating the two pumps in series.

The construction furthermore provides several practical advantages,among them being that the head plates and bearing plates, pump chaniberrings and other parts are either identical or so nearly identical as tobe capable of manufacture up to the last machining operation in commonwith each other. The pump unit may be assembled either at the time ofits original manufacture or after disassembly in the held with the shaftprojecting from either end of p. s. i. It will be noted that thesequence valve I44 is operated by the pressure in the delivery conduitI84 (Figure 3)through passage 202. Thus, so long as the pressure thereinis below the setting of the valve I44, the latter will remain closed,and the entire discharge of the pumps I8 and I8, their combined flow, isdelivered through passage I34. 4

Under these conditions, if the' pump unitll is adapted to drives. fluidmotor, such as a machine tool cylinder, the piston therein will move ata rapid traverse rate. j As resistance to this movement is encounteredeither by meeting the work or by operation of a suitable flow ratereducing valve, the pressurevin the delivery conduit I84 will build upand, being transmitted to the body since the bearing caps areinterchangeable from side to side. I The provision of separate headplates and bearingplates furthermore avoids a diiliculty in that. theexternally exposed bolts on the pump are all of them such that they maybe tightened to any degree without interfering withthe pump action,whereas, if the head plate bolts are exposed, they are frequently pulledup too tight by well-meaning but ignorant workmen.

In addition, the main body casting provides, by means of a few simplecores and a few drilled or bored passages, a complete set of inlet andoutlet passage for two balanced 'vane pumps as ,well as making a housingfor I all of the control valves and providing all of the circuitconnections necessary for automatic series-parallel control of suchpumps. These-- corings and passages moreover-are individually each ofthem of simple and direct form and arranged to carry the flow to andfrom the points where it must be carried by passages of minimum totallength.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other i'orms'in the body and spaced axially from each other,

separate outlet passages, one tor each pump. formed in the body andspaced axially from each other and from the inlet passages, said inletpassages extending radially beyond the pumps proper in one direction andsaid outlet passages extending radially beyond the pumps proper in anopposite direction, the inlet passages being separated and the outletpassages being separated each by a single wall at their extendedportions, a check valve in each of said common walls, and valve meanscontrolling the fluid delivered by said pumps to cause them to operatein parallel through said check valves or in series while said checkvalves remain closed.

2. A multiple pump unit comprising a uni body having a plurality ofpumps mounted therein, a common drive shaft for the pumps. separateinlet passages, one for each .pump, formed in the body and spaced fromeach other, separate 30 outlet passages, one for each pump, formed inthe body and spaced from each other and from the inlet passages, theinlet passages being separated and the outlet passages being separatedeach by a single wall, a pair of check valves in the wall separating theinlet passages and a pair of check valves in the wall separating theoutlet passages, and valve means controlling the fluiddelivered by saidpumps to cause them to operate in parallel through said check valves 'orin series while said check valves remain closed.

3. A multiple pump unit comprising a unitary body having a plurality ofpumps mounted therein, a common drive shaft for the pumps, separateinlet passages, one for each pump, formed in the body and spaced fromeach other. separate outlet passages, one for each pump, formed in thebody and spaced from each other and from the inlet passages, the inletpassages being separated and the outlet passages being separated each bya single wall, a pair of check valves in the wall valves in the wallseparating the outlet passages,

. said check valves being. disposed substantially at the corners of asquare circumsoribing the pumps,

and valve means controlling the fluid delivered by said pumps to causethem to operate in parallel through said check valves or in series whilesaid check valves remain closed. a

' JOHN F. JEANNIN.

